ioo SCIENCE PROGRESS. 



access, while in 16 others the number of crania was less 

 than 10. These deficiencies, both total and partial, are 

 mostly in the east and south-west, the whole of Cataluna 

 and several provinces of Aragon, Valencia and Lower An- 

 dalusia being awanting. The Basque provinces, Asturias, 

 Galicia, Segovia, Cuenca and Toledo, are best represented. 



A still more markworthy work is that of Professor 

 Oloriz, which has but recently appeared. It is a bulky 

 and closely-printed memoir on the geographical distribution 

 of the kephalic index in Spain ; and seldom has a limited 

 though important subject been so thoroughly worked out 

 as this has been by Oloriz. One cannot but be reminded 

 by the labours of these men of the most conspicuous of 

 their national virtues ; De Aranzadi representing the ad- 

 venturous valour of the Basque, Oloriz the dogged, un- 

 conquerable, Numantine perseverance of the Spaniard. 



Oloriz's conclusions are deduced from the measurement, 

 in the great majority of cases by his own hands, of 8368 

 living heads. Having ascertained experimentally that with 

 a total of 100 observations the possible error never reaches 

 unity, and is usually a very small decimal, he took care to 

 secure at least 100 from every province. 



Incidentally, in the course of the definition and explana- 

 tion of his methods, he develops several very important 

 points. 



Thus he shows that the mean error of a single observer 

 (himself) is about 07, and the maximum error about 1*3 

 degree of the kephalic index. The error is apt to be 

 greater, as might be expected, in the length measure than 

 in the breadth measure. The mean extent of error, or 

 divergence from the mean result, when the same head is 

 measured by ten skilled observers, amounts to 178, or 

 about one degree and three-quarters in the kephalic index, 

 the maximum error rising to three degrees. At the first 

 blush, such a result would almost lead one to distrust, and 

 indeed to absolutely discredit, all series of measurements 

 of this kind except those taken by the same pair of hands. 

 This of course would be a mistake : such errors more 

 or less balance each other in long: series and where the 



